Frequently Asked Questions
Everything you need to know about CombinePDF.
How do I combine my first PDF?
It's simple — just drag and drop your PDF files onto the upload area on the homepage, or click to browse. Once you have at least 2 files added, click the Combine button and your merged PDF will download instantly.
Is CombinePDF free to use?
Yes, completely. There are no sign-ups, no payments, and no hidden fees. CombinePDF is free to use forever with no trial limits or restrictions.
Do I need Adobe Acrobat installed?
No. CombinePDF is a standalone web tool that runs entirely in your browser. It does not require Adobe Acrobat or any other software installed on your device.
Are my files safe? Are they uploaded to a server?
Your files never leave your browser. All PDF processing happens locally on your device using browser technology. Nothing is uploaded to any server, so your documents remain completely private.
How many PDF files can I combine at once?
There is no limit. You can combine as many PDF files as you need in a single session. CombinePDF handles large numbers of files with ease.
Can I reorder the PDF files before combining?
Yes. After adding your files, you can drag and drop them in the list to arrange them in any order you want. The final combined PDF will follow that exact order.
Can I combine very large PDF files?
Yes. Unlike many online tools, CombinePDF handles very large PDF documents without issues. Since processing happens in your browser, performance depends on your device's available memory, but large files are fully supported.
What browsers does CombinePDF support?
CombinePDF works on any modern browser including Chrome, Firefox, Safari, and Edge — on both desktop and mobile. No browser extensions or plugins are needed.
What happens if a PDF file fails to load?
If a file fails to load, CombinePDF will show an error message for that specific file. This usually means the file is corrupted or not a valid PDF. You can remove it and try adding it again, or skip it entirely and continue with your other files.
Can I combine PDFs and add bookmarks or a table of contents?
CombinePDF combines your files in the order you set. Automatic table-of-contents and custom bookmark creation is planned for a future update. For now, focus is on fast, reliable merging.